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Kitchen Knife Glossary

Updated - 8/02/11

This is a glossary of kitchen knife related terms. It is intended to help newer members of the forum follow along with the discussions. There are many terms used here that don't connotate their standard definitions, or overlap from other industries and hobbies. It is not by any means an exhaustive list of every specific term used on this forum, especially culinary, Japanese, and metallurgical terms, because those definitions are easily found elsewhere, or are beyond the scope of this site(zknives.com has a great list of Japanese cutlery terms, Steel Composition, and Japanese knife types.)

So if you find yourself wondering what a word means, look it up here! If it's not here, it might be a brand name, or it might still need to be put here.

3 Finger Test – An edge test(highly promoted by Murray Carter), in which the index, middle, and ring fingers of one hand are placed, pads first, perpendicular to the cutting edge and, with slight pressure, rubbed across the edge in short bursts. This test requires lots of practice to provide great insight. It works by alerting the body's response to the sensation of the edge biting into the first few layers of skin, and has been reported to fail to distinguish between dull edges, and sharp ones that are highly polished. Cut fingers are almost guaranteed during the relatively long learning curve for this test. It is not advisable for anyone to try to teach themselves this test without the aid of a teacher or DVD.

Accordion – A piece of vegetable that has been chopped, but left stuck together by a small section of food that went uncut along the bottom. This is almost always undesirable, and often frustrating. It can be prevented by repairing a damaged edge or using proper cutting techniques that compliment the way the knife was designed to be used.

Aggressive – The quality of cutting steel quickly and with little effort

Arkansas Stone – A naturally occurring, dense stone that hails from Arkansas state, which can be lubricated with pretty much anything—water, oil, even some detergents. They are not very aggressive, and they don't have varying abrasive particle sizes. The finer Arkansas Stones are distinguished by greater density, rather than smaller particles. Due to their slow cutting speed, they are often overlooked for harder knives, because it prolongs the sharpening process.

Back of House – The areas of a restaurant customers are not allowed to be in, usually the kitchen.

Back Bevel – The bevel that is behind(closer to the spine than) the cutting edge. Should not be used to denote a bevel on the backside of a single bevel blade.

Bar Stock – Purified steel sold in rectangular shape, sometimes very thick(which is usually used by Bladesmiths to be forged into a knife), or thin(either to layer into a Damascus bar, or cut and ground directly into a knife through stock removal).

Behind the Edge – the portion of a blade just above(closer to the spine than) the primary edge.

Belly – The amount of curvature of the edge between the heel and tip. A large, continuous sweep terminating at a high tip would be considered a “lot of belly”, and a knife whose heel and tip touch the cutting board at the same time is a knife with no belly. More belly is generally better for the rocking motion style of cutting.

Bevel – Any flat plane on a knife. Typically, this refers to the portion of a blade that gets abraded in sharpening. Edges are made up of any number of bevels, but typically 1-4. A single Convex bevel is considered one bevel, though it is made up of many gradual angles. The face is not considered a bevel.

Blade Geometry – The shape of the blade itself, as taken in a cross section from spine to edge. This is often cited as one of the most important and subtle characteristics of a knife. Also see Edge Geometry

Blade Road – The area of a Kata-Ha knife that leads up to the edge bevels. Contains core steel, which is hard and cladding steel, which is soft. Having the softer steel exposed on the blade road makes sharpening less time consuming, as it is easier to work.

Bladesmith – A person who makes knives by forging pieces of purified steel, hammering to shape, grinding, heat treating, and finishing them. A person who does not forge their knives is not a Bladesmith, and a Bladesmith is not the same thing as a Blacksmith. The American Bladesmith Society conducts periodic tests for enterprising Bladesmiths, attaining the rank of “Journeyman” and then “Master” Smith. ABS Master Smith testing, while not required for anything other than the recognition, is a rigorous test of a person's talent and ability at manipulating steel.

Burl – A tree deformation that results in the grain becoming warped, scattered, or twisted. Prized for handles because of the exotic visual appeal.

Burr – A raised edge or small piece of steel remaining attached to the blade after grinding or sharpening. This is a natural byproduct of the sharpening process. Just like modeling clay being formed into peaks by hand will develop uneven, super thin portions the size of your fingers, steel will form the same peaks of weak material the size of the particles being used to abrade it. The solution is to either deburr the edge, or wear it down through a rigorous process of refinement.

Carbon Steel – A steel with less than 13% Chromium. That is all this term implies. It does NOT imply that is is harder, more durable, sharper or otherwise superior. It also does not mean that it needs to be treated like a newborn to keep it from rusting. Basic knife safety and hygiene is enough to prevent rusting and corrosion. A patina can also go a long way to keeping reactivity low. All steel contains Carbon(in addition to Iron, and others), but only steel with less than 13% Chromium is called “Carbon Steel”.

Cell Rot – Short for “Celluloid Rot”, a condition caused by steel(especially carbon steel) being stored for long periods of time in plastic. Over time, the plastic releases gases that react poorly with the steel, causing deep, severe rust pitting and corrosion.

Chasing the Burr – Sharpening on alternate sides of the blade until you can feel or otherwise detect the burr on one side, then abrading it, until it flips to the other side. The goal is to weaken the burr(s) like a tab on a soda can, so that it will eventually pop off when deburring. Chasing the burr is not necessary if you are handling burrs and wire edges through careful and complete refinement.

Chop – An informal term for a direct push-cutting technique, in which the blade is lifted, and dropped straight down on to the food. This causes abuse from the cutting board because the edge is being smacked into the board over and over. End grain cutting boards are the most gentle on a blade, and are sometimes called “chopping blocks”.

Clad Construction – A blade design in which a harder steel is “sandwiched” between two pieces of softer steel. This allows for many benefits. It makes sharpening easier on kata-ha knives, because the soft steel is easier to abrade than the harder core steel. It also can save reduce cost by only using the high quality, hard steel for the part that actually does the cutting. Softer steel tends to be less brittle, so it reduces the chance that impact will shatter or crack the knife. Some makers use carbon steel for the core and stainless for the cladding, in an effort to give their knives “the best of both worlds”--the edge characteristics of carbon steel, and the overall maintenance of stainless—the edge itself, however will still rust and patina as normal.

Clad Line – the visible line where 2 types of steel meet that were clad together. Not to be confused with a temper line or hamon.

Claw – A hand safety technique used when cutting. The hand used for holding the food is held in a shape like it is holding a ball, and the food is held with the fingertips, and the knuckles are bent slightly and placed against the face of the blade. Food is pushed through the claw by the thumb. A technique of choice for professionals, because they can’t afford to lose their fingers.

Combo Stone – A sharpening Stone that has a low grit on one side, and a higher grit on the other, like having 2 thinner stones in one package. There are a few rare coticule stones that formed in the Earth against layers of different stone, and were cut precisely to create a natural combo stone. These are very rare and not being quarried anymore. 99.9% of combo stones are synthetic.

Compound – an abrasive that has been combined with a substance that aids in distribution over a strop. Can be a spray, liquid, cream, paste, wax, etc.

[aname=convex]Convex – Literally, 'bulging outward'. Refers to the shape of a grind that is slightly rounded. A convex edge bevel, done properly, is just as effective as any other, and a slight amount of convexing is considered helpful on the faces to help release food and prevent sticking and wedging.

Coticule – A natural stone from Europe, prized by the straight-razor community. While less hard than Arkansas Stones, they are not as aggressive as Japanese Natural stones. They are not commonly used for kitchen knives, because it allows a straight razor to get a smooth, nuanced edge, that will cut hair and not skin, and this edge is rarely desired for kitchen knives.

Custom – A very general term for a knife that is designed to suit a person's particular tastes. Could be the customer's taste, and it could be the maker's.

Cutler – A useful, but oddly scarce term for a person who makes or otherwise supplies knives, straight razors, scissors, axes, or other edged implements.

Cutting Edge – The part of the knife that actually cuts the food, the point created where 2 planes come together to form a peak. Edge grinds can be complex, with 2 or more bevels; this term refers to the bevel that contacts the food and board first.

Damascus – A catch-all term for patterned steel. It can be stainless or carbon steel, and made from many different types of steel, and is not always a sign of quality. This a complex subject, and involves many overlapping terms. 'Damascus Steel' was a famous sword material from hundreds of years ago, hailing from modern day Syria. It was a high carbon steel, tempered at low temperatures many times, and developed carbide structures that looked like wavy lines—this was an art that was lost for a long time, and is not used today in kitchen knives. Different types of steel can be blended together, resulting in a (somewhat) similar pattern, and this is what is often called “Damascus” steel. True Damascus steel is very interesting to look at, and a real testament to a Bladesmith's talent and patience, but it does not provide enhanced performance beyond the individual qualities of the the steels it contains. The pattern is brought out through etching in acid, and will fade over time(requiring re-etching), despite the fact that it is a pattern IN the steel, not just on the surface. There are many, many different ways to create these patterns.

Deburring – The act of removing a burr. This can be done by many means, but the common method is to cut into something like cork, rubber or ultra-rock-hard felt, as these substances provide pressure on all directions and the friction to pull the tiny burrs off. The immediate result of deburring is that the burrs formed are literally torn off, so if you deburr after sharpening on a low grit medium, it is advisable to continue on to higher grits, deburring after each stone, and building up a minimum burr on the next higher stone. It is theoretically possible to sharpen and raise a burr so tiny it is undetectable before stopping intentionally, but it is NOT possible to meet both planes of a bevel on the cutting edge without raising any kind of burr, at least not using sharpening stones. Removal of a wire edge is the same as deburring, since a wire edge is a type of burr.

Deformation – A more specific word for dulling, refers to the loss of the proper structure of the edge, be it through chipping, bending, rolling, or otherwise.

Differential Heat Treat – A process in which one section of a single piece of steel is heat treated differently than another section. This process was created for swords, to enable a single piece of high quality steel to be hardened on it's edge and maintain a sharp, durable angle, but the steel on the spine would be soft, allowing for flexibility to prevent the sword from breaking in high-impact situations. In kitchen knives, it is mostly tradition and aesthetics, though there are some who profess to notice a feeling of “liveliness” in blades treated this way.

Dishing – The slow, inevitable formation of low spots on a sharpening stone, due to uneven surface wear. A dished stone, when used as normal, will create a more convexed edge than intended, and might roll the edge. Usually dealt with by lapping or occasional flattening with a variety of coarser mediums.

Edge – The part of a knife that is physically altered to improve the cutting characteristics of a knife. The purpose of an edge is to provide a strong, sharp, and easy to maintain interface between the knife and it’s target. An edge is made up of 1 or more bevels

Edge Failure – The sudden dulling of a cutting edge through chipping, bending, or any other deformation. This can be a sign of defective steel, but almost always indicates a poor quality or erroneous sharpening job.

Edge Geometry – The shape and angles of the Bevels. This is one of the aspects of a knife's design that is most commonly altered on a knife. Simply using a different angle than the factory used is changing the geometry. Also see Blade Geometry

Edge Grain – A piece of wood that is cut with the grain so that the grain is parallel to the surface. This is common in less expensive cutting boards, because it is easier to make—planks of wood typically are cut with the grain, since that is how the tree grows.

Edge Profile – The general design and shape of the edge, as seen when looking directly at the face. One of the most important qualities of a knife. The qualities that make a great edge profile are nuanced and depend largely on the applied technique and personal preference. The edge profile is often altered, providing for more/less/different belly, but is best left to those with experience with such alterations, as it is easy to create a problem with the symmetry of the bevels or an overgrind.

Edge Test – Any of a wide variety of cutting tasks that a knife is put through to determine it's cutting characteristics. While many tests can be useful and informative, the only surefire test that a knife is working well is to use it to cut what it was intended to cut.

End Grain – A piece of wood that is cut across the grain so that the grain is perpendicular to the surface. This is common in the very best cutting boards, because the grain can separate to allow a knife to cut into it without damaging the wood too severely, and without abrading the edge unnecessarily.

Face – The side of the blade above the edge, usually emblazoned with some kind of logo. The face of a knife is not always flat.

Figured – Refers to the quality of wood having a visually interesting grain structure. Wood with very unusual or complex patterns is referred to as “highly figured”. Plain-looking wood can be said to “not exhibit much(or any) figuring.”

Filework – Decorative grooves and patterns ground into the edge of a bar of metal, usually on the tang and/or spine. While aesthetically pleasing, it serves no function, and may actually house food particles, and therefore frowned upon for professional food service use

Finger Point – A grip in which the handle is grasped with 4 fingers around the handle, and the index finger is place, pad first, on the spine of the knife. This is a good grip for slicing, but does not provide a lot of security, so inexperienced cooks are advised against this grip. Very common for sushi chefs, where there is not any downward pressure needed to make cuts.

Fit and Finish – The level to which an object is functionally and aesthetically refined. Usually refers to level of polish, tightness of the fittings, quality of the overall grind, any extra time and effort spent at the end of the knife making process.

Forge – Either an object or a process. A Forge is a very hot(thousands of degrees) oven, used by [URL”http://www.kitchenknifeforums.com/showthread.php?2023-Kitchen-Knife-Glossary#bladesmith]bladesmiths[/URL] to heat steel to make it malleable. Forging is the practice of using a forge to make a knife. Technically, any knife that is heated for the purpose of shaping through impact or pressure can be called “forged”, and it is often used as a marketing term.

Freehand – Sharpening knives by hand, without the aid of a stabilizing device, or jig. With time and practice, sharpeners improve in their ability to maintain a steady angle, and create a more precise edge. Due to the complex nature of the human body, a perfectly flat bevel is impossible to achieve. This does not necessarily mean that the edge is less precise, as a certain amount of convexing is considered acceptable or even desirable.

Front of House – The areas of a restaurant customers are allowed to be in.

Full Tang – Handle design in which the tang shares a silhouette with the handle scales, and is visible all the way around. Often touted as better quality for kitchen knives, but this only helps in heavy abuse situations, like sword fighting, and is kept around in kitchen cutlery for tradition's sake and aesthetic appeal.

Grabby – The quality of an edge to cut into food instantly when slicing.

Grantons – shallow indentations behind the edge that are intended to keep food from sticking by allowing air between the blade and the food. The effectiveness(or lack thereof) of grantons is a subject of debate.

Grit – A scale denoting the average particle size of an abrasive. The higher the grit, the smaller the particle, and the finer a finish it will leave. American and Japanese Grits are not the same, and there are many different grit ratings, even in the same country, and not all manufacturers' stated grits are accurate. There are many charts available to convert different grits into Micron size, which is a much more reliable scale. Generally, 'rough' grits are about 25-200 Microns, 'medium' grits are about 5-25 Microns, and 'fine' grits are less than 5 microns.

Grind – The way a knife is shaped, formed or forged at different parts. A blade can have different grinds, such as a hollow ground blade with a flat edge bevel. Ex: “a convex grind”. See Hollow Ground, Convex, and Flat grind.

Guide – A (usually small and simple) object that is attached to a knife that helps to maintain a steady angle. The angle will change depending on how wide the blade is and where the guide is attached. Specially tailored guides can be helpful, but there is no guide that will work for every size, shape and style of blade.

Hammered Finish – A texture created on the face of a knife by repeated striking, usually with a metal punch. Mostly aesthetic value, as it does not really keep food from sticking. Food does not get stuck in the dimples so long as basic knife hygiene and safety are applied.

Hammer Grip – A grip in which the knife is held with all five fingers wrapped around the handle, like one would hold a hammer.

Hammer-In – An organized social get-together of knifemakers at a shop, for the purpose of making and discussing knives, sharing good company, and eating and drinking.

Hanging Hair Test – An edge test in which a single hair is drawn across a motionless blade, in an attempt to break or at least whittle it

Haze – A contrasting finish left on a kasumi blade, achieved through careful honing/polishing. The abrasive needs to be hard enough to scratch the soft cladding, but small and evenly distributed enough to polish the core steel. An ideal Kasumi finish would be one in which the soft steel cladding and hard core steel contrast each other, without deep scratches.

Heat Treat– The process of heating and cooling steel, in varying patterns and ranges, to produce desirable characteristics in the steel. Differs from the forging process, because the steel is not being heated for the purpose of being shaped or hammered. Any shape change during heat treating is referred to as warpage.

High-Carbon – Any Steel that contains more than .5% Carbon. Often this term is just marketing, since .5% carbon is really not much(some go as high as 3.8%[MPL-1]), and many steels qualify for this term, despite being heat treated poorly or even made up of an altogether undesirable alloy.

Hone – A generic term for sharpening, but often used to denote use of a honing rod.

Honing Rod – A cylindrical rod used for minor touchups and maintenance of an edge between sharpening sessions, to keep the edge at peak performance. While it is a common item, it is very rare to see one used correctly, on television, in pro kitchens, or anywhere. The purpose is to gently re-align the teeth of a knife that are bent through normal use, making the edge feel “fresh” again. Steel rods are made of a steel hardened to around HRC 61, which is hard enough to align teeth on a knife of soft steel, about HRC 59 or less. Harder knives do not respond well to steel hones, because they are often harder than the hone itself, or they become dull through micro chipping, literally breaking *teeth* off instead of bending them. These knives benefit from glass, ceramic or borosilicate rods, though many prefer to simply strop their hard steel knives between sharpening.

House Knives – Restaurant industry term for the knives the restaurant owns, as opposed to the knives cooks bring and maintain themselves. Typically these “beaters” are inexpensive, poorly cared for, and make up the bulk of what is used to prepare your food outside your house. Rarely, there are restaurants that supply good quality knives to their staff.

Jig – Any device used to mount either the knife, stone, or both, to aid in maintaining a precise angle, and remove the element of human error from the sharpening process. Given hard sharpening media, a “dead flat” bevel is achievable, but this does not necessarily mean the edge is more precise, as a certain amount of convexing is considered acceptable, or even desirable. There are many, many of these available, but only a few work well enough to use on a wide variety of quality cutlery.

Kasumi – Japanese for 'mist', also the name for clad construction. It refers to the [URL=http://www.kitchenknifeforums.com/showthread.php?2023-Kitchen-Knife-Glossary#haze]haze traditionally left on the blade.

Kata-Ha – The Japanese term for a style of single-bevel knife construction. Often pronounced “Kah-tah-bah”.

Knife Callous – The internationally recognized sign of a working cook. A small rough patch of skin on the index finger that is caused by abrasion from using a knife for hours at a time, day after day.

Knifemaker – A person who makes knives. Does not denote any specific method of knifemaking.

Kuro-Uchi – A “rustic” finish where the scale from the forge is not removed in the process of making a knife. Provides a moderate amount of corrosion resistance, similar to a patina. This also allows the maker to skip a step in finishing the blade, and can help to reduce cost, making otherwise pricy steel a little more accessible.

Lapping – abrading a stone during a sharpening session with a flatter, coarser medium, to make the stone flat, and/or to quickly build up mud. Not everyone laps their stones, but flattening at least occasionally is advised to prevent dishing.

Laser – Slang for a knife that is very sharp and very thin. Often this is a subjective assessment.

Lineup – A particular progression of sharpening stones, hones, strops and other sharpening tools. A person's chosen “lineup” is so named because often the stones are laid out in a row on a table, and used one after another. Does not imply that these are the only stones the person owns, just the ones being used.

Loading – Can mean 2 things, but both with the same basic meaning—having a rough surface coated with tiny particles. (1) The act of coating a strop with a compound to aid in edge refinement (2) The effect of swarf being left behind and depositing on a Sharpening Stone, which can damage the stones cutting speed and apparent grit size—this is never a desirable occurance.

Marker Trick – A sharpening aid process in which a permanent marker is used to color over the entire edge up to the cutting edge, and given a few seconds to dry before proceeding with normal sharpening. The hone being used will abrade away the surface, and will reveal what part(s) of the bevel is making consistent contact with the stone, by removing the ink. Be careful not to not shade it too high if you don't want any of the marker left on the face of the knife behind the edge.

Marketing Term – Legitimately useful words whose meanings is either vague or obscure enough to allow them be used by unscrupulous vendors to misrepresent an item. When a knife's ad copy says something like “100% forged german steel with a tempered blade”, it is like saying you are selling a soccer ball that is “100% stitched American leather with a high-pressure inflated bladder”. They are designed to sound overly impressive to a casual user, and combating the deception they are used for is one of the purposes of this list.

Micarta – A heavy-duty handle material made with fabric that is layered and impregnated in a vacuum with plastic resin. Good micarta will not shrink, warp, crack, absorb water, or wear easily. Can be made into many different colors or patterns. Common on outdoor knives.

Microbevel – A bevel that is very small, and never the primary bevel. The purpose of a microbevel is to increase the strength of the cutting edge(because it creates a less acute angle), and the process of adding one can help in the removal of burrs and wire edges, because the cutting edge is being directly abraded. A microbevel always makes up the cutting edge, but not all edges have microbevels.

Mighty – Complimentary slang for a knife that is thick or heavy. Often this is a subjective assessment.

Mokume – Short for Mokume-Gane, A traditional Japanese metal laminate, used for sword fittings, literally “burl metal”. Many metals are layered and softened, they are forged and shaped to the desired pattern. It is a difficult and challenging process, even for skilled smiths.

Mud – The mixture of lubricant/water, stone particles, and swarf created as a byproduct when a knife is sharpened on a stone. Sometimes this is undesirable, as it can create a slippery surface and prevent the blade from touching the stone, but it is critical in the use of many Waterstones, where it does most of the real cutting work. A stone that wears quickly will create a lot of mud, a quality referred to as “muddy”. An authentic Kasumi finish is created by using very fine, very muddy natural stones.

Natural Stone – Any stone that is used for sharpening that is harvested from nature, rather than manufactured. Depending on what type of stone they are, they may work best with water, oil, or soap. Japanese Natural stones are a soft binder with very hard particles, and work best when allowed to build up mud. Because they are organic products, there is a lot of variation from stone to stone, even from the same quarry, so best if they are tested by an expert before being purchased.

Oilstone - A sharpening stone that was designed to be lubricated with oil, can be natural(like an Arkansas stone) or synthetic.

Overgrind - A defect in a blade where too much steel was removed. It causes a dip in the surface, which may or may not be noticable. If the overgrind occurs in a way that interferes with the cutting edge, it will cause a rise in the edge profile, and the knife will not make full board contact.

Paper Test – An Edge Test in which a piece of paper is held by it's edge with two fingers and a knife is pushed into the edge of the paper to determine it's ability to push cut without tearing or crumpling the paper. Thinner the paper, the more difficult this is, cheap newsprint or receipt ticket paper is often used.

Passaround – A great benefit of being a long-term or well-known member on this forum! A passaround generally has its own rules, but typically a knife is mailed off to a person who gets to use it for a few days, before mailing it to yet another person. The knife is handed off around the country, or even the globe, to be tested/experienced, only for the cost of shipping it to the next person, ensuring it’s safety, and offering insightful feedback on the knife itself. Enterprising knifemakers will use these to get feedback from a wide variety of knowledgeable users, or sometimes just a specific group, such as professional cooks.

Patina – A thin layer of protective oxidation that forms naturally on a carbon steel blade from exposure to reactive substances. A patina can help prevent further oxidation, rust, and/or corrosion by forming an even coating of (often dark-colored)protective compounds. One can “force” a patina by intentional exposure to reactive substances, commonly mustard, beef, or vinegar, sometimes even in specific patterns. Patina can also help prevent the blade from forming sulphur-smelling chemicals when it contacts certain foods, like cabbage. Stainless steel will not develop a patina.

Penny Trick – A traditional Japanese sharpening aid process in which 2 pennies are stacked on a stone and the spine of a knife is held against them. This is intended to provide a visual and tactile sample of the very acute angles traditional Japanese knives are intended to be kept at. This is not a precise aid by any means, because, like a guide it suffers from the fact that a taller blade will produce a more acute angle, and a narrower blade will produce a more obtuse angle.

Permasoak – Leaving a stone in water when not in use. Some stones can survive this, others will crack or become so soft, they essentially dissolve.

Pinch Grip – A grip in which the knife is held by the bolster area, with the index finger and thumb pinching the blade. Pressure is applied with the palm of the hand and the side of the index finger. This is the professional grip of choice, and, when used all day, everyday, leads to finger callouses.

Polished Edge – An edge that has been highly refined, so the cutting edge has a mirror-like surface. Usually this means the cutting edge itself has been taken to a very high grit. This type of edge is preferred for push cutting.

Profile – The silhouette of a blade. A blade's profile is not just aesthetic, it affects how it performs, because it changes how the knife distributes weight/force, how well supported the tip and edge are, where the balance point is, etc.

Pull-Through Sharpener – Any sharpening device that operates by having a “v-shaped” arrangement of abrasives that the knife is drawn through. Some are powered by motors, have wheels, ceramic/diamond rods, or any manner of contraptions. These type of sharpeners are frowned upon for most all occasions, because they leave a very ragged edge, do not adapt to different angles and cannot compensate for blade thickness/hardness/etc. It is strongly advised to avoid using these on any tools you care about, and want to work to their full potential.

Push Cut – Either a technique, or a cutting direction. A push-cut is pushing the edge perpendicular to the object, straight through it. A fantastic push cutting edge requires a high level of precise refinement. Generally, when used to refer to a cutting technique, it refers to a sort of “locomotive” style motion, where the knife leaves the cutting board between every cut, and is pushed downward and forward. This is a gentle motion if done correctly(because little pressure is needed and board contact is minimized), and helps to prevent chipping on brittle blades. Use of the claw. Is recommended with this grip, since it is easy to lift the blade too high and cut your fingers.

Reactivity – The tendency of a steel to form new chemical compounds when contacted with different foods. A very reactive steel can go from mirror-like shiny to dull grey from cutting through one head of cabbage. The reactivity of a steel is caused by many different factors, from it's chemical composition, to it's physical structure.

Refining – Refers to the process of sharpening an edge to a high grit, to achieve a uniform polish and a very smooth, toothless edge. The more steps one takes between the low and high grits, the less time will be required on the finest(often most expensive) stones. A quality refined edge takes time, skill, good tools, and is the only way to get great push-cutting edges.

Rehandle – The act of removing an old, undesired handle and fitting it with a new one. Sometimes this is done as a spare-time project for handy folks, but it is a common upgrade for well-loved knives, or great blades that come with unappealing handles.

Reprofile – The act of grinding a knife to change the profile. Often done to repair abused knives, or flatten knives that have more belly than they owner would like.

Rocking Motion – A cutting motion in which the knife never loses contact with the cutting board. The heel is lifted, and the belly glides up, and the tip area remains on the board. The cut is made by simply pressing downward, guiding the knife along it’s edge until the heel touches the board. This is a traditional European technique(taught in culinary schools along with the claw). It takes abuse from the cutting board because it is constantly cutting into the board. End grain cutting boards are the most gentle on a blade, but if a rocking motion is used while moving the knife sideways, resulting in twisting the knife on the board, the board can gouge. This is a good way to teach children to cut, as it reduces the odds the knife will be dropped, or leave it's cutting board. Similar to walking.

Roll the Edge – The act of sharpening, stropping, or honing at an angle that is not acute enough, causing the cutting edge to be worn down, effectively dulling a knife instead of sharpening it. Can also happen(if the steel is soft enough) when the edge is scraped against a board to move food(which is never recommended).

Saya – A wooden sheath, traditionally used to house a Katana. The traditional method of construction is to cut a piece of wood in half, carve a cavity in one piece of the wood that fits the shape of the blade exactly, and then glue it back to the other flat piece, matching the grain to its original state. When done correctly, it looks like one piece of wood, never separated. There are many other, more modern ways of making these, and they are very popular upgrades/features of high end knives. The knife is usually held in by means of a wooden pin that is fitted just behind the choil of the knife, though there are many other ways of securing it.

Scale – Can refer to either a handle part or a byproduct of forging. Typically “Scales” are the pieces of material used to make a western handle. Some suppliers sell wood in sets of matching scales, to be made into handles straightaway. “Scale” is the term for the black, uneven layer that is left on steel after being forged. Some steel suppliers sell bars of steel that have been “de-scaled”, or cleaned up before sale. Kuro-Uchi finishes are achieved by simply leaving the forge scale on the blade, which, although perhaps unappealing to some, does not affect the performance of the steel(though it is a bit more difficult to keep dry due to the craggy surface).

Serrations – Protrusions in an edge, designed to either saw through food, or increase the edge motion. Very common on cheap knives, since a dull saw will rip up food for a long time. Some serrations are very hard to maintain, some are relatively easy. Often reserved in quality cutlery for bread knives(though they are not always used on bread!).

Sharpening Steel – A steel rod for honing a knife, to re-align the teeth. A misnomer, because the steel rods do not sharpen, and the rods that sharpen are not made of steel. See honing rod.

Sharpening Stone – A block, in varying sizes, intended to remove steel from a knife by abrading it. The stone contains particles that are harder than the carbides in the steel, and the harder they are, the faster they cut. No matter how hard they are, all stones wear down and need to be either maintained or replaced. Some require soaking in water beforehand, some do not. Collecting stones is a popular rabbit-hole to fall into, as there are so many synthetic choices available, and naturals often have qualities that are unique to each stone.

Shave Test – An edge test in which dry, untreated body hair(usually arm or leg hair) is shaved off. Not to be confused with an actual shaving test, where a blade(usually a straight razor, because that's what they are for) is used to shave the face with soap and water.

Single-Bevel – a knife with an obtuse bevel on one side, and no bevels on the other. Typically, the bevel is on the right for right handed users, and on the left for left handed users. This does have a tendency to create a steering problem if done poorly.

Sink Bridge – A surface for placing waterstones across the span of a kitchen sink, to provide a stable surface to sharpen on that is also easy to clean up. Can be anything from a complex manufactured product to a simple plank laid across a sink with a wet cloth on it.

Slice – A cutting motion in which the blade is pulled or pushed forward, often implying gentle or no pressure. Most slicing work does not result in a lot of board contact.

Splash and Go – A stone that requires no soaking, only a light coat of water—you just “splash and go”.

Stabilized – A process of enhancing wood by putting it in a container with resin, and vacuuming out all the air, which causes the resin to be soaked up by the wood. This prevents the wood from wearing easily, absorbing water, shrinking, warping, cracking, expanding, or discoloring, and makes fragile woods easy to work with.

Stainless Steel – A steel with over 13% Chromium. This is all this term means. It does NOT mean that it will not rust, stain, or corrode. It also does not mean that the steel is soft, weak or otherwise inferior—there are a whole world of very fine quality stainless steels today. A stainless steel knife will not develop a patina.

Steeling – Use of a Steel honing rod to re-align the teeth on a soft(less than HRC 59) steel knife, which will bend out of alignment through normal use and board contact. The steel in these rods is usually HRC 62, which is softer than many knives, and is therefore useless.

Steering – the tendency of a knife to pull to the left or right during a cut, making pieces thicker or thinner at the bottom than they are at the top. This can be caused by the user's grip, but is generally a sign of a knife that is either very dull, incorrectly sharpened, or improperly made.

Stock Removal Method – A knifemaking method in which the blade is not forged to the final shape of the knife, but instead is cut out of a bar or sheet of steel, heat treated, and ground to shape. While this is a perfectly valid method of knifemaking, some prefer the more rustic appeal of a forged knife. A major downside of this method is that a lot of(often pricey, high quality) steel is wasted as swarf. A knifemaker who makes knives exclusively through Stock Removal is not a Bladesmith.

Strop – Any permanent device used for Stropping. Typically leather mounted on a wood base, a leather strap(common for straight razors), or bare balsa wood, but a strop can be made out of lots of things, with fine-grained leather being the longtime favorite.

Stropping – Stropping differs from sharpening in that the purpose is to “clean up” the edge by polishing the cutting edge and removing teeth, not to create a new burr or grind away much metal. Stropping is done on many fine substrata, but is always done with the edge trailing, meaning that the stroke is pulled spine first. When held at the proper angle, pushing edge-first will cause the edge to bite into the strop, which is one of the main reasons edge trailing strokes are used. When stropping, it is critical that the cutting edge is being abraded—too acute an angle, and it will simply polish the shoulder, not acute enough, and you will likely roll the edge. Strops are often loaded to increase their aggressiveness.

Sun – A traditional Japanese unit of measure, equal to 3.03milimeters or 1.19inches

Swarf – Metal debris. It is one of 3 ingredients in stone mud, and is often used as a metonym for such.

Synthetic Stone – Any sharpening stone that is manufactured, rather than harvested from nature. There are almost as many types, styles, and varieties of these stones as you can imagine, from all parts of the world, especially Japan.

Take Down – A knife that is made with scales that are not glued or fixed on the tang, but instead are bolted on, so that the handle can be changed at a later date, or removed to make serious alterations to the blade. Sometimes this is done to test a different knife design without sacrificing time and materials remaking handle scales.

Taper – There are 2 kinds of taper, Profile Taper and Distal Taper. Usually “Taper”, when used by itself, refers to a Profile Taper, or the rate at which the knife shortens from heel to tip. Distal Taper is the rate at which a blade thins in thickness from it's heel to it's tip. A “true” Distal Taper is one that is proportional all the way, as measured with a micrometer. This helps the knife provide cutting power and an even feel.

Teeth – Microscopic serrations left on the cutting edge after sharpening. All edges will have 'teeth' on some level, but it requires great magnification to detect, it won't even reflect significant enough light to see with the naked eye. A more toothy edge is achieved by simply stopping the sharpening process at a lower grit. Not to be confused with actual Serrations.

Tempering – A very complex process that uses heat to convert different compounds and structures in the steel into other, more desirable compounds and structures.

Thick in the Back – Slang for a knife that has a wide spine in relation to it's other proportions. Often this is a subjective assessment.

Tomato Test – An edge test in which a tomato is the target. Tomatoes are commonly used in cooking and have both soft flesh(which likes a polished edge) and rubbery skin(which likes a toothy edge), so they provide a fairly versatile test medium.

Too Sharp – Inaccurate slang for an edge that has been too highly refined. Many edge tests are designed to test a blade's ability to push cut, and are not always the best indicator of how a kitchen knife will perform with different foods. A knife made of poor design and cheap steel can be sharpened so that it shaves arm hair easily, but won't cut through a potato, giving it the feeling that it is “too sharp”.

Toothy – An edge which has not been highly polished. This kind of edge will be grabbier and is preferred for most slicing applications, though it will not push-cut well. See Teeth

Wa – Japanese term denoting a hidden-tang knife handle that is round, d-shaped, or octagonal handle, common on traditional Japanese cutlery. Also see Yo.

Walking – A cutting motion in which the knife is held sideways by the handle in one hand(with the bolster sticking out between the thumb and index finger), and the other hand holds the spine(either pinched, or with the flat of the palm). The blade is rocked along it’s edge and moved around the board, hence the name “walking”. Commonly applied to herbs and aromatics in order to mince them.

Warpage --- The distortions in a blade's intended shape caused by an uneven heat treat. This is sometimes fixable, but never desirable. It is not always an error, very thin blades will often warp during heat treat despite doing everything else correctly. Despite the fact that the heat treating process will make the steel harder to grind, many makers do as much grinding as possible after heat treat, simply to prevent warpage.

Wedging – The tendency of wider, flatter blades to get stuck in hard or large food items, such as potatoes. While some people do not mind, this is never considered a positive trait.

Western – A knife handle that is anything but a Wa handle. Usually this means a Full Tang construction with scales, but can be essentially anything that is not a Wa handle.

Wire Edge – A burr that is uniform, and runs the length of the cutting edge. Often mistaken by novice sharpeners for a satisfactory edge. Though it is very sharp, it is structurally weak, and due to the hard use kitchen knives see, it will need to be removed, or the edge will fail.

Yo – Japanese word denoting a knife handle that is of a Western tradition. Also see Wa.

I'm a little confused now about aogami steel classifications.
I was under the understanding that blue and blue #2 were aogami steels while aogami super was blue super.
Does blue #2 and blue super have the same chemical properties?

I'm a little confused now about aogami steel classifications.
I was under the understanding that blue and blue #2 were aogami steels while aogami super was blue super.
Does blue #2 and blue super have the same chemical properties?

You are right! I will alter that. Aogami is really all that is needed, since I do not want to cross the line into a steel glossary. An exhaustive list of steels, and their makeup was done by Gator at zknives, and it is a great resource!